Feederhouse gearboxes with reverser worm drives and combine harvesters equipped with the same

Abstract

Feederhouse gearboxes are provided for installation on combine harvesters. In embodiments, the feederhouse gearbox includes a gearbox housing, an output shaft rotatable about an output axis, and a primary drive input. The primary drive input is mechanically linked to an engine of the combine harvester when the feederhouse gearbox is installed thereon. A reverser drive input is mechanically linked to a reverser motor of the combine harvester when the feederhouse gearbox is installed on the combine harvester. The feederhouse gearbox further includes a selector mechanism within the gearbox housing and movable between a primary drive position and a reverser drive position, a primary gear train transmitting rotation from the primary drive input to the output shaft when the selector mechanism is in the primary drive position, and a reverser worm drive transmitting rotation from the reverser drive input to the output shaft when the selector mechanism is in the reverser drive position.

What is claimed is: 
     
       1. A feederhouse gearbox for installation on a combine harvester including an engine and a reverser motor, the feederhouse gearbox comprising:
 a gearbox housing; 
 an output shaft mounted to the gearbox housing for rotation about an output axis; 
 a primary drive input rotatably mounted to the gearbox housing and mechanically linked to the engine when the feederhouse gearbox is installed on the combine harvester; 
 a reverser drive input rotatably mounted to the gearbox housing and mechanically linked to the reverser motor when the feederhouse gearbox is installed on the combine harvester; 
 a selector mechanism within the gearbox housing and movable between a primary drive position and a reverser drive position; 
 a primary gear train transmitting rotation from the primary drive input to the output shaft when the selector mechanism is in the primary drive position; and 
 a reverser worm drive transmitting rotation from the reverser drive input to the output shaft when the selector mechanism is in the reverser drive position. 
 
     
     
       2. The feederhouse gearbox of  claim 1 , wherein the primary gear train provides a first speed reduction when transmitting rotation from the primary drive input to the output shaft; and
 wherein the reverser worm drive provides a second speed reduction when transmitting rotation from the reverser drive input to the output shaft, the second speed reduction greater than the first speed reduction. 
 
     
     
       3. The feederhouse gearbox of  claim 1 , wherein the primary gear train comprises a planet-carrier assembly including planet gears supported by a carrier, the planet-carrier assembly rotatable relative to the gearbox housing about the output axis. 
     
     
       4. The feederhouse gearbox of  claim 3 , wherein the primary gear train further comprises:
 a sun gear engaging the planet gears and rotatable relative to the gearbox housing about the output axis; and 
 a ring gear circumscribing the sun gear, engaging the planet gears, and rotationally fixed relative to the gearbox housing. 
 
     
     
       5. The feederhouse gearbox of  claim 4 , wherein rotation is transferred from the sun gear, through the planet-carrier assembly, and to the output shaft when the feederhouse gearbox is installed on the combine harvester, the engine drives rotation of the primary drive input, and the selector mechanism is in the primary drive position. 
     
     
       6. The feederhouse gearbox of  claim 4 , further comprising a gerotor within the gearbox housing and mechanically coupled to the planet-carrier assembly, the gerotor urging lubricant flow into the gearbox housing when driven by rotation of the planet-carrier assembly. 
     
     
       7. The feederhouse gearbox of  claim 3 , wherein the reverser worm drive comprises:
 a worm; and 
 a worm gear engaged by the worm and rotatable about the output axis; 
 wherein rotation is transferred from the worm, through the worm gear, and to the output shaft when the feederhouse gearbox is installed on the combine harvester, the reverser motor drives rotation of the reverser drive input, and the selector mechanism is in the reverser drive position. 
 
     
     
       8. The feederhouse gearbox of  claim 7 , wherein the reverser drive input comprises a shaft projecting from the gearbox housing and coupled to the worm in a rotationally-fixed relationship. 
     
     
       9. The feederhouse gearbox of  claim 1 , further comprising an indexing ring coupled to the output shaft for co-rotation therewith;
 wherein the selector mechanism further comprises a selector collar engaging the indexing ring and slidable with respect thereto between:
 a first position in which the selector collar mechanically couples a first rotatable member included in the primary gear train to the indexing ring; and 
 a second position in which the selector collar mechanically couples a second rotatable member included in the reverser worm drive to the indexing ring. 
 
 
     
     
       10. The feederhouse gearbox of  claim 9 , wherein the first rotatable member and the second rotatable member comprise a carrier and a worm gear, respectively. 
     
     
       11. The feederhouse gearbox of  claim 1 , wherein the reverser motor comprises a hydraulic motor having a motor output shaft mechanically linked to the reverser worm drive; and
 further comprising:
 a controller; and 
 a proportional control valve operably coupled to the controller and hydraulically coupled to the hydraulic motor, the controller operable in a modality in which the controller commands the proportional control valve to repeatedly switch between driving the motor output shaft in a first rotational direction and in a second rotational direction when the selector mechanism is in the reverser drive position. 
 
 
     
     
       12. A feederhouse gearbox for installation on a combine harvester including an engine and a reverser motor, the feederhouse gearbox comprising:
 a gearbox housing; 
 an output shaft mounted to the gearbox housing for rotation about an output axis; 
 a primary drive input rotatably mounted to the gearbox housing and mechanically linked to the engine when the feederhouse gearbox is installed on the combine harvester; 
 a reverser drive input rotatably mounted to the gearbox housing and mechanically linked to the reverser motor when the feederhouse gearbox is installed on the combine harvester; 
 a primary gear train contained in the gearbox housing, the primary gear train comprising:
 a ring gear coupled to the gearbox housing in a rotationally-fixed relationship therewith; 
 a sun gear within the gearbox housing, co-axial with the ring gear, and rotatable about the output axis; and 
 a planet-carrier assembly within the gearbox housing, co-axial with the ring gear and the sun gear, and rotatable about the output axis; 
 
 a reverser worm drive, comprising:
 a worm contained in the gearbox housing; and 
 a worm gear engaged by the worm and rotatable about the output axis; and 
 a selector mechanism controllable to selectively mechanically couple (i) the planet-carrier assembly to the output shaft when the feederhouse gearbox operates in a first modality and (ii) the worm gear to the output shaft when feederhouse gearbox operates in a second modality. 
 
 
     
     
       13. The feederhouse gearbox of  claim 12 , further comprising a gerotor within the gearbox housing and mechanically coupled to the planet-carrier assembly, the gerotor configured driven by rotation of the planet-carrier assembly to urging lubricant flow into the gearbox housing. 
     
     
       14. The feederhouse gearbox of  claim 12 , further comprising an indexing ring coupled to the output shaft for co-rotation therewith;
 wherein the selector mechanism further comprises a selector collar engaging the indexing ring and slidable with respect thereto between:
 a first position in which the selector collar mechanically couples a first rotatable member included in the primary gear train to the indexing ring; and 
 a second position in which the selector collar mechanically couples a second rotatable member included in the reverser worm drive to the indexing ring. 
 
 
     
     
       15. The feederhouse gearbox of  claim 12 , wherein the planetary gear train provides a first speed reduction when transmitting rotation from the primary drive input to the output shaft; and
 wherein the reverser worm drive provides a second speed reduction when transmitting rotation from the reverser drive input to the output shaft, the second speed reduction greater than the first speed reduction. 
 
     
     
       16. The feederhouse gearbox of  claim 12 , wherein the reverser motor comprises a hydraulic motor having a motor output shaft mechanically linked to the reverser worm drive; and
 further comprising:
 a controller; and 
 a proportional control valve operably coupled to the controller and hydraulically coupled to the hydraulic motor, the controller operable in a modality in which the controller commands the proportional control valve to repeatedly switch between driving the motor output shaft in a first rotational direction and in a second rotational direction when the selector mechanism is in the reverser drive position. 
 
 
     
     
       17. A combine harvester, comprising:
 an engine; 
 a reverser motor; and 
 a feederhouse gearbox comprising:
 a gearbox housing; 
 an output shaft rotatably mounted to the gearbox housing; 
 a primary drive input rotatably mounted to the gearbox housing and mechanically linked to the engine; 
 a reverser drive input rotatably mounted to the gearbox housing and mechanically linked to the reverser motor; 
 a selector mechanism within the gearbox housing and movable between a primary drive position and a reverser drive position; 
 a primary gear train transmitting rotation from the primary drive input to the output shaft when the selector mechanism is in the primary drive position; and 
 a reverser worm drive transmitting rotation from the reverser drive input to the output shaft when the selector mechanism is in the reverser drive position. 
 
 
     
     
       18. The combine harvester of  claim 17 , wherein the reverser motor comprises a hydraulic motor having a motor output shaft mechanically linked to the reverser worm drive. 
     
     
       19. The combine harvester of  claim 18 , further comprising:
 a controller; and 
 a proportional control valve operably coupled to the controller and hydraulically coupled to the hydraulic motor, the controller operable in a modality in which the controller commands the proportional control valve to repeatedly switch between driving the motor output shaft in a first rotational direction and in a second rotational direction when the selector mechanism is in the reverser drive position. 
 
     
     
       20. The combine harvester of  claim 18 , wherein the primary gear train comprises:
 a planet-carrier assembly including planet gears supported by a carrier, the planet-carrier assembly rotatable relative to the gearbox housing about an output axis; 
 a sun gear engaging the planet gears and rotatable relative to the gearbox housing about the output axis; and 
 a ring gear circumscribing the sun gear, engaging the planet gears, and rotationally fixed relative to the gearbox housing. 
 
     
     
       21. The combine harvester of  claim 20 , wherein the reverser worm drive comprises:
 a worm contained in the gearbox housing; and 
 a worm gear engaged by the worm and rotatable about the output axis. 
 
     
     
       22. The combine harvester of  claim 21 , wherein, when in the primary drive position, the selector mechanism rotationally couples the planet-carrier assembly to the output shaft, while rotationally decoupling the worm gear therefrom; and
 wherein, when in the reverser drive position, the selector mechanism rotationally couples the worm gear to the output shaft, while rotationally decoupling the planet-carrier assembly therefrom. 
 
     
     
       23. The combine harbester of  claim 20 , further comprising a gerotor within the gearbox housing and mechanically coupled to the planet-carrier assembly, the gerotor urging lubricant flow into the gearbox housing when driven by rotation of the planet-carrier assembly. 
     
     
       24. The combine harvester of  claim 17 , further comprising an indexing ring coupled to the output shaft for co-rotation therewith;
 wherein the selector mechanism further comprises a selector collar engaging the indexing ring and slidable with respect thereto between:
 a first position in which the selector collar mechanically couples a first rotatable member included in the primary gear train to the indexing ring; and 
 a second position in which the selector collar mechanically couples a second rotatable member included in the reverser worm drive to the indexing ring. 
 
 
     
     
       25. The combine harvester of  claim 17 , wherein the primary gear train provides a first speed reduction when transmitting rotation from the primary drive input to the output shaft; and
 wherein the reverser worm drive provides a second speed reduction when transmitting rotation from the reverser drive input to the output shaft, the second speed reduction greater than the first speed reduction.